FR 41. Intensive production of « Martinik » hair sheep at grazing in Martinique (F.W.I.)
Local hair sheep are the main small ruminants in Martinique (F.W.I.) with more than 37 000 heads. This paper reports an overview of the performances of «Martinik» hair sheep recorded from 1978 to 1996 in an experimental and extension farm belonging to the local council, located in southern dry region of Martinique. The rainfall ranges between 1250 to 1500 mm/year with a marked dry season during 7 months. The reproduction was conducted in 3 mating per 2 years with 3 seasons of mating: dry season (April), mild season (August) and wet season (December). Lambs were weaned at 85 days of age. Two flocks of ewes were reared during 5 years on irrigated or not irrigated grazing systems based on Digitaria decumbens (Dd). The irrigation increased the fertility rate (P<.05); the prolificacy rate (P<.01); annual productivity of ewes, and surface productivity. Two flocks of ewes were reared during 4 years in two grazing systems: Digitaria decumbens vs Cynodon nlemfuensis (Cn). Herbage mass availability on Cn paddocks was higher than on the Dd paddocks (P<.01). Fertility and prolicacy rates were not affected by the type of forage. The mortality rate from birth to weaning was higher for Cn flock than for the Dd flock (P<.01). The milk production in 70 day of lactation reared on Dd was higher than for Cn (P<.01). The daily weight gain (DWG) 10-30 and 30-70 days of age adjusted for sex, litter size and lambing season were 175 vs 147 g/d (P<.01) and 137 vs 120 g/d , respectively for lambs reared on Dd and Cn. However, in our conditions, it appeared that Cn is not adapted to sheep grazing. The third trial was carried out to set up system that will decrease adverse effects of intensification. The association of cattle to growing lambs increased by 23 % the total meat production per ha (P<.01). Mix grazing decreased the infection risk of sheep by H. contortus, so that it is was assumed that it would be possible to decrease drenching rate. It also decreases herbage mass and improve nutritive value of available forage.